Improvement in burglar-alarms



H. HART. Burglar-Alarm.

No. 201,008. Patented March 5, 1878.

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N. PETERS, FHOTO-LITHOGHAPHER. WASHINGTON D C.

llEp-um i a 55:2: W geese HORACE HART, OF LITTLE VALLEY, NEW YORK.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent N0. 201,008, dated March 5, 1878; application filed January 19, 1878.

To all whom it may concern:

Be it known that I, HORACE HART, of Little Valley, in the county of Oattaraugus and State of New York, have invented a new and valuable Improvement in Burglar-Alarms; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, makinga part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a plan View of my burglar-alarm with the gong removed, and Fig. 2 is a transverse vertical section of the same.

The nature of this invention relates to that class of burglar-alarms which are operated by turning the door-knob; and it consists in certain improvements, as will be hereinafter more fully set forth, and pointed out in the claims.

The annexed drawing, to which reference is made, fully illustrates the invention.

A represents a door, with lock B. G is the spindle, with knobs D D on opposite sides of the door. Above the lock, on the inner side of the door, is secured a base-plate, E, with central post G projecting therefrom, and on the same is screwed or otherwise fastened the gong or bell H. On each side of and below thecenter post to a suitable stud, a, are pivoted elbow-levers I, the lower vertical arms of which two levers are connected by a spring, b, substantially as shown, said spring holding these arms against lugs 11 b in their normal position.

To the outer ends of the horizontal arms of the elbow-levers are attached the bell-ham mers J J.

The vertical arm of each lever I is provided with a slide or sliding foot, K, which is hung upon a pin, cl, passing through a slot, 0, in said foot. This foot, when the parts are in their normal position, hangs between the lug b and a lug, f, projecting from the side of the lever; and the lower edge of the foot is cam-shaped, as shown at h, with a projection, t, on the outer side.

On the tube or shank of the knob Dis fastened a collar, L, with arm L projecting therefrom. This arm is provided with an extension, L having a longitudinal slot, m, through which a set-screw, R, passes into the arm L to securely hold said extension to the arm. The extension L is, on its upper end, provided with 2. lug, n, which extends forward, as shown.

The collar L is so arranged on the knobshank that when the lock-bolt is in its normal position the extension-arm L will project up between the two feet K K of the levers I I, provided said extension has been extended or drawn up as far as it will admit. By now turning either knob in either direction for opening the door, the lug n on the arm L will strike one of the feet K on its inner edge near the lower end; and as said foot bears against the lugf upon its lever, it follows that the lever is turned on its pivot, and as soon as the lug n clears the foot K the spring a suddenly returns the lever to its position, and causes the hammer to sound the alarm. The knob, of course, immediately returns to its former position when the hand is removed from it, and the lug n, in returning, strikes the camface h of the foot, so as to raise or lift the same out of the way. The foot then drops down again in position.

During the day-time, if no alarm is desired, the extension L is pushed down along the arm L by loosening the set-screw B, so that the lug n can pass under the feet K without operating the alarm.

O is a guard attached to the door, for holding the arm L and its extension in position.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination of the elbow-lever I, with hammer J and lug f, stationary lug b, and the sliding foot K, having cam-edge h, substantially as and for the purposes set forth.

2. The elbow-levers I, provided with the slotted sliding feet K, suspended from the pins d, substantially as described.

In testimony that I claim the above I have hereunto subscribed my name in the presence of two witnesses.

HORACE HART.

Witnesses:

WILLARD GOULD, E. A. NASH. 

